<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>

<div class="container">
    <div>子元素1</div>
    <div>子元素2</div>
    <div>子元素3</div>
</div>

</body>
</html>